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2.
Acta Neuropathol Commun ; 7(1): 155, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619292

RESUMO

Glioblastoma cell ability to adapt their functioning to microenvironment changes is a source of the extensive intra-tumor heterogeneity characteristic of this devastating malignant brain tumor. A systemic view of the metabolic pathways underlying glioblastoma cell functioning states is lacking. We analyzed public single cell RNA-sequencing data from glioblastoma surgical resections, which offer the closest available view of tumor cell heterogeneity as encountered at the time of patients' diagnosis. Unsupervised analyses revealed that information dispersed throughout the cell transcript repertoires encoded the identity of each tumor and masked information related to cell functioning states. Data reduction based on an experimentally-defined signature of transcription factors overcame this hurdle. It allowed cell grouping according to their tumorigenic potential, regardless of their tumor of origin. The approach relevance was validated using independent datasets of glioblastoma cell and tissue transcriptomes, patient-derived cell lines and orthotopic xenografts. Overexpression of genes coding for amino acid and lipid metabolism enzymes involved in anti-oxidative, energetic and cell membrane processes characterized cells with high tumorigenic potential. Modeling of their expression network highlighted the very long chain polyunsaturated fatty acid synthesis pathway at the core of the network. Expression of its most downstream enzymatic component, ELOVL2, was associated with worsened patient survival, and required for cell tumorigenic properties in vivo. Our results demonstrate the power of signature-driven analyses of single cell transcriptomes to obtain an integrated view of metabolic pathways at play within the heterogeneous cell landscape of patient tumors.

3.
Brain Behav Immun ; 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31059805

RESUMO

Microglia cells are the immune effector in the Central Nervous System (CNS). However, studies have showed that they contribute more to glioma progression than to its elimination. Rutin and its aglycone quercetin are flavonoids present in many fruits as well as plants and have been demonstrated to bear anti-inflammatory, antioxidant and antitumor properties also to human glioblastoma cell lines. Previous studies also demonstrated that rutin, isolated from the Brazilian plant Dimorphandra mollis Bent., presents immunomodulatory effect on astrocytes and microglia. In this study, we investigate the antitumor and immunomodulatory properties of rutin and its aglycone quercetin on the viability of glioma cells alone and under direct and indirect interaction with microglia. Flavonoid treatment of rat C6 glioma cells induced inhibition of proliferation and migration, and also induced microglia chemotaxis that was associated to the up regulation of tumor necrosis factor (TNF) and the down regulation of Interleukin 10 (IL-10) at protein and mRNA expression levels, regulation of mRNA expression for chemokines CCL2, CCL5 and CX3CL1, and Heparin Binding Growth Factor (HDGF), Insulin-like growth factor (IGF) and Glial cell-derived neurotrophic factor (GDNF) growth factors. Treatment of human U251 and TG1 glioblastoma cells with both flavonoids also modulated negatively the expression of mRNA for IL-6 and IL-10 and positively the expression of mRNA for TNF characterizing changes to the immune regulatory profile. Treatment of microglia and C6 cells either in co-cultures or during indirect interaction, via conditioned media from glioma cells treated with flavonoids or via conditioned media from microglia treated with flavonoids reduced proliferation and migration of glioma cells. It also directed microglia towards an inflammatory profile with increased expression of mRNA for IL-1ß, IL-6, IL-18 and decreased expression of mRNA for nitric oxide synthase 2 (NOS2) and prostaglandin-endoperoxide synthase 2 (PTGS2), arginase and transforming growth factor beta (TGF-ß), as well as Insulin-like growth factor (IGF). Treatment of U251 cells with flavonoids also reduced tumorigenesis when the cells were xenotransplanted in rat brains, and directed microglia and also astrocytes in the microenvironment of tumor cell implantation as well as in the brain parenchyma to a not favorable molecular inflammatory profile to the glioma growth, as observed in cultures. Together these results demonstrate that the flavonoid rutin and its aglycone quercetin present antiglioma effects related to the property of modulating the microglial inflammatory profile and may be considered for molecular and preclinical studies as adjuvant molecules for treatment of gliomas.

4.
Nat Commun ; 10(1): 2235, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138805

RESUMO

Pediatric high-grade glioma (pHGG) and diffuse intrinsic pontine gliomas (DIPGs) are aggressive pediatric brain tumors in desperate need of a curative treatment. Oncolytic virotherapy is emerging as a solid therapeutic approach. Delta-24-RGD is a replication competent adenovirus engineered to replicate in tumor cells with an aberrant RB pathway. This virus has proven to be safe and effective in adult gliomas. Here we report that the administration of Delta-24-RGD is safe in mice and results in a significant increase in survival in immunodeficient and immunocompetent models of pHGG and DIPGs. Our results show that the Delta-24-RGD antiglioma effect is mediated by the oncolytic effect and the immune response elicited against the tumor. Altogether, our data highlight the potential of this virus as treatment for patients with these tumors. Of clinical significance, these data have led to the start of a phase I/II clinical trial at our institution for newly diagnosed DIPG (NCT03178032).


Assuntos
Adenoviridae , Neoplasias do Tronco Encefálico/terapia , Glioma/terapia , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Neoplasias do Tronco Encefálico/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Simulação por Computador , Modelos Animais de Doenças , Glioma/patologia , Humanos , Técnicas In Vitro , Camundongos , Gradação de Tumores , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Oncotarget ; 10(7): 773-784, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30774779

RESUMO

Some cancer cells elongate their telomeres through the ALT (alternative lengthening of telomeres) pathway, which is based on homologous recombination for the addition of telomere repeats without telomerase activity. General control non-derepressible 5 (GCN5) and P300/CBP-associated factor (PCAF), two homologous lysine acetyltransferases, exert opposite effects on the ALT pathway, inhibiting or favoring it respectively. Here we show that ALT cells are particularly sensitive to the inhibition of acetyltransferases activities using Anacardic Acid (AA). AA treatment recapitulates the effect of PCAF knockdown on several ALT features, suggesting that AA decreased the ALT mechanism through the inhibition of lysine transferase activity of PCAF, but not that of GCN5. Furthermore, AA specifically sensitizes human ALT cells to radiation as compared to telomerase-positive cells suggesting that the inhibition of lysine acetyltransferases activity may be used to increase the radiotherapy efficiency against ALT cancers.

8.
Pharmaceut Med ; 33(3): 187-191, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31933285

RESUMO

For more than 40 years, scientists have been developing tools and technologies for genome modification; however, initial progress was slow and few outside of the molecular biology community took an interest in the field. Everything has dramatically changed with the recent appearance of the so-called precision approaches, and especially with the 'CRISPR (Clustered Regularly Interspaced Short Palindromic Repeat) revolution'. With great powers come great responsibilities. CRISPR-derived technologies have been proven efficient, cheap, rather easy and fast, and provided universal access to genome modification techniques beyond the leading research centers and reference laboratories. The popularization of techniques to manipulate the human genome and that of all other living beings consequently raises many essential questions, on the ethical and legal sides, both for the scientific community and the lay public. In order to mitigate excessive hype and concern among citizens, a call for the mobilization of the various stakeholders is now urgent through a global governance of genome editing.

9.
Oncotarget ; 9(43): 27197-27219, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29930759

RESUMO

Glioblastoma is a highly heterogeneous brain tumor. The presence of cancer cells with stem-like and tumor initiation/propagation properties contributes to poor prognosis. Glioblastoma cancer stem-like cells (GSC) reside in hypoxic and acidic niches favoring cell quiescence and drug resistance. A high throughput screening recently identified the laxative Bisacodyl as a cytotoxic compound targeting quiescent GSC placed in acidic microenvironments. Bisacodyl activity requires its hydrolysis into DDPM, its pharmacologically active derivative. Bisacodyl was further shown to induce tumor shrinking and increase survival in in vivo glioblastoma models. Here we explored the cellular mechanism underlying Bisacodyl cytotoxic effects using quiescent GSC in an acidic microenvironment and GSC-derived 3D macro-spheres. These spheres mimic many aspects of glioblastoma tumors in vivo, including hypoxic/acidic areas containing quiescent cells. Phosphokinase protein arrays combined with pharmacological and genetic modulation of signaling pathways point to the WNK1 serine/threonine protein kinase as a mediator of Bisacodyl cytotoxic effect in both cell models. WNK1 partners including the Akt and SGK1 protein kinases and NBC-family Na+/HCO3- cotransporters were shown to participate in the compound's effect on GSC. Overall, our findings uncover novel potential therapeutic targets for combatting glioblastoma which is presently an incurable disease.

10.
Sci Rep ; 8(1): 3664, 2018 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-29483558

RESUMO

Despite continuous improvements in treatment of glioblastoma, tumor recurrence and therapy resistance still occur in a high proportion of patients. One underlying reason for this radioresistance might be the presence of glioblastoma cancer stem cells (GSCs), which feature high DNA repair capability. PARP protein plays an important cellular role by detecting the presence of damaged DNA and then activating signaling pathways that promote appropriate cellular responses. Thus, PARP inhibitors (PARPi) have recently emerged as potential radiosensitizing agents. In this study, we investigated the preclinical efficacy of talazoparib, a new PARPi, in association with low and high linear energy transfer (LET) irradiation in two GSC cell lines. Reduction of GSC fraction, impact on cell proliferation, and cell cycle arrest were evaluated for each condition. All combinations were compared with a reference schedule: photonic irradiation combined with temozolomide. The use of PARPi combined with photon beam and even more carbon beam irradiation drastically reduced the GSC frequency of GBM cell lines in vitro. Furthermore, talazoparib combined with irradiation induced a marked and prolonged G2/M block, and decreased proliferation. These results show that talazoparib is a new candidate that effects radiosensitization in radioresistant GSCs, and its combination with high LET irradiation, is promising.


Assuntos
Ftalazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glioblastoma/metabolismo , Humanos , Transferência Linear de Energia/efeitos dos fármacos , Transferência Linear de Energia/fisiologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Radiossensibilizantes , Transdução de Sinais/efeitos dos fármacos
14.
Acta Neuropathol ; 135(2): 267-283, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29149419

RESUMO

Although a growing body of evidence indicates that phenotypic plasticity exhibited by glioblastoma cells plays a central role in tumor development and post-therapy recurrence, the master drivers of their aggressiveness remain elusive. Here we mapped the changes in active (H3K4me3) and repressive (H3K27me3) histone modifications accompanying the repression of glioblastoma stem-like cells tumorigenicity. Genes with changing histone marks delineated a network of transcription factors related to cancerous behavior, stem state, and neural development, highlighting a previously unsuspected association between repression of ARNT2 and loss of cell tumorigenicity. Immunohistochemistry confirmed ARNT2 expression in cell sub-populations within proliferative zones of patients' glioblastoma. Decreased ARNT2 expression was consistently observed in non-tumorigenic glioblastoma cells, compared to tumorigenic cells. Moreover, ARNT2 expression correlated with a tumorigenic molecular signature at both the tissue level within the tumor core and at the single cell level in the patients' tumors. We found that ARNT2 knockdown decreased the expression of SOX9, POU3F2 and OLIG2, transcription factors implicated in glioblastoma cell tumorigenicity, and repressed glioblastoma stem-like cell tumorigenic properties in vivo. Our results reveal ARNT2 as a pivotal component of the glioblastoma cell tumorigenic signature, located at a node of a transcription factor network controlling glioblastoma cell aggressiveness.


Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias Encefálicas/metabolismo , Cromatina/metabolismo , Glioblastoma/metabolismo , Idoso , Animais , Translocador Nuclear Receptor Aril Hidrocarboneto/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Células Cultivadas , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Glioblastoma/genética , Glioblastoma/patologia , Código das Histonas , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Fatores do Domínio POU/metabolismo , Fatores de Transcrição SOX9/metabolismo
15.
Cancer Cell ; 32(6): 856-868.e5, 2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29198914

RESUMO

While molecular subtypes of glioblastoma (GBM) are defined using gene expression and mutation profiles, we identify a unique subpopulation based on addiction to the high-affinity glucose transporter, Glut3. Although Glut3 is a known driver of a cancer stem cell phenotype, direct targeting is complicated by its expression in neurons. Using established GBM lines and patient-derived stem cells, we identify a subset of tumors within the "proneural" and "classical" subtypes that are addicted to aberrant signaling from integrin αvß3, which activates a PAK4-YAP/TAZ signaling axis to enhance Glut3 expression. This defined subpopulation of GBM is highly sensitive to agents that disrupt this pathway, including the integrin antagonist cilengitide, providing a targeted therapeutic strategy for this unique subset of GBM tumors.


Assuntos
Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Transportador de Glucose Tipo 3/metabolismo , Integrina alfaVbeta3/metabolismo , Transcriptoma , Animais , Antineoplásicos/farmacologia , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Glioblastoma/mortalidade , Humanos , Estimativa de Kaplan-Meier , Camundongos , Camundongos Nus , Transdução de Sinais , Venenos de Serpentes/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Camb Q Healthc Ethics ; 26(4): 701-704, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28937352
17.
Transgenic Res ; 26(5): 709-713, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28730514

RESUMO

In this consensus paper resulting from a meeting that involved representatives from more than 20 European partners, we recommend the foundation of an expert group (European Steering Committee) to assess the potential benefits and draw-backs of genome editing (off-targets, mosaicisms, etc.), and to design risk matrices and scenarios for a responsible use of this promising technology. In addition, this European steering committee will contribute in promoting an open debate on societal aspects prior to a translation into national and international legislation.


Assuntos
Biotecnologia/tendências , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Biotecnologia/métodos , Europa (Continente) , Humanos
18.
Oncotarget ; 8(16): 26269-26280, 2017 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-28412741

RESUMO

Cancer cells can use a telomerase-independent mechanism, known as alternative lengthening of telomeres (ALT), to elongate their telomeres. General control non-derepressible 5 (GCN5) and P300/CBP-associated factor (PCAF) are two homologous acetyltransferases that are mutually exclusive subunits in SAGA-like complexes. Here, we reveal that down regulation of GCN5 and PCAF had differential effects on some phenotypic characteristics of ALT cells. Our results suggest that GCN5 is present at telomeres and opposes telomere recombination, in contrast to PCAF that may indirectly favour them in ALT cells.


Assuntos
Estudos de Associação Genética , Homeostase do Telômero/genética , Telômero/genética , Fatores de Transcrição de p300-CBP/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Expressão Gênica , Técnicas de Silenciamento de Genes , Instabilidade Genômica , Humanos , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/metabolismo , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patologia , Ligação Proteica , Troca de Cromátide Irmã , Translocação Genética
19.
Cell Death Dis ; 8(3): e2713, 2017 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-28358371

RESUMO

Glioblastomas are incurable primary brain tumors that affect patients of all ages. The aggressiveness of this cancer has been attributed in part to the persistence of treatment-resistant glioblastoma stem-like cells. We have previously discovered the tumor-suppressor properties of the microRNA cluster miR-302-367, representing a potential treatment for glioblastoma. Here, we attempted to develop a cell-based therapy by taking advantage of the capability of glioma cells to secrete exosomes that enclose small RNA molecules. We engineered primary glioma cells to stably express the miR-302-367. Remarkably, these cells altered, in a paracrine-dependent manner, the expression of stemness markers, the proliferation and the tumorigenicity of neighboring glioblastoma cells. Further characterization of the secretome derived from miR-302-367 expressing cells showed that a large amount of miR-302-367 was enclosed in exosomes, which were internalized by the neighboring glioblastoma cells. This miR-302-367 cell-to-cell transfer resulted in the inhibition of its targets such as CXCR4/SDF1, SHH, cyclin D, cyclin A and E2F1. Orthotopic xenograft of miR-302-367-expressing cells together with glioblastoma stem-like cells efficiently altered the tumor development in mice brain.


Assuntos
Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , MicroRNAs/biossíntese , Família Multigênica , Proteínas de Neoplasias/biossíntese , RNA Neoplásico/biossíntese , Animais , Terapia Baseada em Transplante de Células e Tecidos , Glioblastoma/genética , Glioblastoma/terapia , Humanos , Camundongos , MicroRNAs/genética , Proteínas de Neoplasias/genética , RNA Neoplásico/genética
20.
Biochim Biophys Acta Mol Cell Res ; 1864(6): 1018-1027, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28109792

RESUMO

Glioblastoma is the most common malignant brain tumor. The heterogeneity at the cellular level, metabolic specificities and plasticity of the cancer cells are a challenge for glioblastoma treatment. Identification of cancer cells endowed with stem properties and able to propagate the tumor in animal xenografts has opened a new paradigm in cancer therapy. Thus, to increase efficacy and avoid tumor recurrence, therapies need to target not only the differentiated cells of the tumor mass, but also the cancer stem-like cells. These therapies need to be effective on cells present in the hypoxic, slightly acidic microenvironment found within tumors. Such a microenvironment is known to favor more aggressive undifferentiated phenotypes and a slow-growing "quiescent state" that preserves the cells from chemotherapeutic agents, which mostly target proliferating cells. Based on these considerations, we performed a differential screening of the Prestwick Chemical Library of approved drugs on both proliferating and quiescent glioblastoma stem-like cells and identified bisacodyl as a cytotoxic agent with selectivity for quiescent glioblastoma stem-like cells. In the present study we further characterize bisacodyl activity and show its efficacy in vitro on clonal macro-tumorospheres, as well as in vivo in glioblastoma mouse models. Our work further suggests that bisacodyl acts through inhibition of Ca2+ release from the InsP3 receptors.


Assuntos
Bisacodil/farmacologia , Neoplasias Encefálicas/patologia , Sinalização do Cálcio , Glioblastoma/patologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Glioblastoma/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo
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